I have a Barco Data 600 that is like brand new BUT will not respond to the convergence controls (red & blue plastic controls). I have switched on the convergence and as I do so the picture pulls in as if the control is doing something. I am able to alter all the other controls under the main cover (picture size, skew etc). I have checked to see if the 2 plugs from the convergence panel are plugged in and also checked for any bent pins on these plugs. Anybody got any ideas ?